[net v6 05/12] ch_ktls: Correction in trimmed_len calculation

[Rohit Maheshwari]

trimmed length calculation goes wrong if skb has only tag part
to send. It should be zero if there is no data bytes apart from
TAG.

Fixes: dc05f3df8fac ("chcr: Handle first or middle part of record")
Signed-off-by: Rohit Maheshwari <roh...@chelsio.com>
---
 .../chelsio/inline_crypto/ch_ktls/chcr_ktls.c         | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c 
b/drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c
index 950841988ffe..4286decce095 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c
+++ b/drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c
@@ -1729,10 +1729,13 @@ static int chcr_short_record_handler(struct 
chcr_ktls_info *tx_info,
 
        if (remaining_record > 0 &&
            remaining_record < TLS_CIPHER_AES_GCM_128_TAG_SIZE) {
-               int trimmed_len = data_len -
-                       (TLS_CIPHER_AES_GCM_128_TAG_SIZE - remaining_record);
-               /* don't process the pkt if it is only a partial tag */
-               if (data_len < TLS_CIPHER_AES_GCM_128_TAG_SIZE)
+               int trimmed_len = 0;
+
+               if (tls_end_offset > TLS_CIPHER_AES_GCM_128_TAG_SIZE)
+                       trimmed_len = data_len -
+                                     (TLS_CIPHER_AES_GCM_128_TAG_SIZE -
+                                      remaining_record);
+               if (!trimmed_len)
                        goto out;
 
                WARN_ON(trimmed_len > data_len);
-- 
2.18.1